Phenolic hydroxyl-containing compounds, used in adhesives, molding materials, paints, photoresist materials, raw materials for epoxy resins, curing agents for epoxy resins, etc., have also been utilized as the main ingredient of curable resin compositions and curatives for epoxy or other resins in various fields of electrical and electronics engineering, including semiconductor sealants and insulating materials for printed circuit boards, because of the superior characteristics they exhibit in the cured form, such as superb heat and moisture resistance.
One of such fields is photoresists. To be used as photoresists, not only should coatings be resistant to heat, they should have properties such as alkali solubility and light sensitivity. In the multilayer resist scheme, currently under active development as a method for the formation of more detailed wiring patterns than in the existing resist schemes, one or more layers called bottom resist film(s) or anti-reflective coating(s) are formed on a substrate, a resist pattern is formed on the layer(s) by conventional photolithography, and then dry etching is performed to transfer the wiring pattern to the substrate. An important component in the multilayer resist technology is the bottom resist film(s). The bottom film(s) needs to have, for example, high resistance to dry etching, low resist-pattern line edge roughness (LER), low optical reflection, and high resistance to thermal decomposition. The resin material for the bottom resist film(s), which is diluted in a medium prior to the formation of the film(s), needs to be soluble in commonly used organic solvents. Some modes of formation of the resist pattern require that the uncured resin composition for the bottom film(s) have certain performance characteristics, such as solubility in alkaline developers and the capability of being removed during the development of the photoresist.
Some known phenolic hydroxyl-containing compounds superior in heat resistance include a dihydroxynaphthalene novolac resin (see PTL 1) and a phenolic hydroxyl-containing compound that has the cylindrical structure called calixarene (see PTL 2). As for phenolic hydroxyl-containing compounds for bottom resist films, a known example is a fluorene-containing compound that has a molecular structure represented by the structural formula below (see PTL 3).

Of these, the dihydroxynaphthalene novolac resin described in PTL 1 fails to achieve the required level of heat resistance, which has been increasingly high in recent years, although highly resistant to heat when compared with typical phenol novolac resins, and resists prepared therefrom are inferior in sensitivity and resolution. The 1-naphthol-based calix(4)arene described in PTL 2 is not sufficiently soluble in commonly used organic solvents and therefore are difficult to use in adhesive, paint, photoresist, and printed circuit board applications. The fluorene-containing compound described in PTL 3 is highly soluble in commonly used organic solvents and gives low optical reflection to coatings prepared by curing the compound, but does not meet the currently required level in terms of dry-etch and thermal decomposition resistance. There is a need to develop a phenolic compound for bottom resist films that combines higher dry-etch and thermal decomposition resistance.